Primary hyperoxaluria causing ESRD and gangrene of extremities leading to amputation

Primary hyperoxaluria is an uncommon, inherited metabolic disorder due to hepatic enzyme deficiencies with consequent hepatic oxalate overproduction and attendant systemic complications. The diagnosis is established on a combination of clinical parameters, elevated urinary excretion of oxalate and glycolate and determination of alanine glyoxylate aminotransferase in the liver tissue. We describe a 45-year-old female with end-stage renal disease secondary to nephrolithiasis, who presented with a fulminating vascular syndrome before confirming the diagnosis of primary hyperoxaluria. This case illustrates that in this infrequent clinical entity, the diagnosis is often delayed with incorrect initial management.     

Poor correlation between coronary artery calcification and obstructive coronary artery disease in an end-stage renal disease patient

Vascular calcification is highly prevalent and often severe in patients with chronic kidney disease. Arterial calcification in patients with chronic kidney disease can result from the deposition of mineral along the intimal layer of arteries in conjunction with atheromatous plaques or from calcium deposition in the medial wall of arteries, also known as Monckeberg's sclerosis. Whether coronary artery calcium scores as measured by electron beam computed tomography correlate with occlusive atherosclerotic disease in the dialysis population is uncertain. Here we report a case of an asymptomatic patient with diabetes mellitus and end-stage renal disease undergoing maintenance hemodialysis, who was found to have extremely elevated coronary artery calcium scores on electron beam computed tomography, but varied degrees of atherosclerotic plaque in her coronary arteries on coronary angiography. This suggests that in addition to the calcification anticipated in a remodeled intima, a proportion of the calcification is also likely to be in the arterial media. Thus, this case demonstrates that even an extremely high coronary calcium score may not be a satisfactory surrogate marker for obstructive atherosclerosis in elderly diabetic dialysis patients.     

Beck Depression Inventory-Fast Screen (BDI-FS): an efficient tool for depression screening in patients with end-stage renal disease

Depression is common in patients suffering from end-stage renal disease (ESRD). Various screening tools for depression in ESRD patients are available. This study aimed to validate the Beck Depression Inventory-Fast Screen (BDI-FS) with the Beck Depression Inventory-II (BDI-II) as depression screening tool in conventional hemodialysis (CHD) patients. One hundred sixty two CHD patients were studied with both screening questionnaires. We used the Pearson Correlation Coefficient to measure the agreement between BDI-II and BDI-FS scores from 134 patients who responded to both questionnaires. Receiver operating characteristics curve and area under the curve were constructed to determine a valid BDI-FS cutoff score to identify ESRD patients at risk for depression. BDI-II and BDI-FS scores strongly correlated (Pearson r = 0.85, p < 0.0001). At a BDI-II cutoff ≥16, receiver operating characteristics showed the best balance between sensitivity and specificity for the BDI-FS cutoff value of ≥4 with a sensitivity of 97.2% (95% confidence interval [CI]: 85.5%, 99.9%) and a specificity of 91.8% (95% CI: 84.5%, 96.4%). When applying the above cutoff scores, prevalence of depressive symptoms in all completed questionnaires was found to be 28.7% (BDI-II) and 30.1% (BDI-FS), respectively. The BDI-FS was found to be an efficient and effective tool for depression screening in ESRD patients which can be easily implemented in routine dialysis care.     

Characteristics of heart rate variability entropy and blood pressure during hemodialysis in patients with end-stage renal disease

Entropy (ENT) is a newly developed measure of the complexity of heart rate variability (HRV). The aim of this study was to characterize the complexity of HRV in patients with end-stage renal disease (ESRD) and to find a possible clinical utility. Healthy subjects and patients with ESRD undergoing hemodialysis (HD) were recruited. The HD population consisted of patients with and without diabetes mellitus (DM). An electrocardiogram was recorded before HD, and blood pressure was measured during HD. The coefficients of variation of R-R intervals, high- and low-frequency components, and ratio of the low- to high-frequency components were measured as variables of HRV. The ENT was used to describe the complexity of HRV. Forty-six healthy subjects and 27 HD patients participated in this study. The ENT negatively correlated with the duration of DM (p = 0.001), systolic blood pressure (p = 0.003), and mean blood pressure (p = 0.004) before a HD session. ENT in HD patients was lower than that in healthy subjects (p < 0.01). ENT in HD patients with DM was lower than that in HD patients without DM (p < 0.01). The change in systolic blood pressure (DeltaSBP) during a HD session showed high correlations to ENT and ultrafiltration rate (UFR) of the dialyzer. The following equation was obtained: DeltaSBP = 2.25 x ENT - 2.28 x UFR - 21.27 (R2 = 0.805; p < 0.0001). ENT decreased with uremic and diabetic status. ENT also represents a possible prediction of hypotension during a HD session.     

Calcium-sensing receptor gene polymorphisms and cardiac valvular calcification in patients with chronic renal failure: A pilot study

Cardiac valvular calcification (VC) is a frequent finding in chronic hemodialysis patients. In addition to demographic and metabolic factors, genetic susceptibility may also influence the occurrence and severity of these abnormalities and account for interindividual variability among patients. In this report, we studied the relation of calcium-sensing receptor (CaSR) gene polymorphisms to the development of VC in chronic hemodialysis patients. A total of 41 chronic hemodialysis patients (26 male, mean age 47.23 ± 11.36 years vs. 15 females, mean age 48.13 ± 14.66 years) undergoing treatment for more than 1 year were evaluated with transthoracic echocardiography. In patients with and without VC, CaSR gene polymorphisms (A990G, C1011G) were investigated by PCR, using allele-specific primers. In randomly chosen subjects, PCR analysis was verified by DNA sequencing. Cardiac valve calcification was detected in 21 patients (51.2%). Five of these patients (12.2%) had mitral valve calcification, 4 (9.75%) had aortic valve calcification, and 12 (29.27%) had both. In patients with VC, the frequency of the A/G genotype was slightly higher than those with no VC with a borderline P value (42.9% vs. 15%, χ²=3.840, P=0.050). The frequency of the C/C genotype was similar in patients with and without VC (90.5% vs. 85%, P>0.05). The results of this study are not enough to prove the role of CaSR gene polymorphisms in the development of VC. There is a need for large-scale studies on this topic.     

Simultaneous sensing of the strain and points of failure in composite beams with an embedded fiber optic Michelson sensor

A fiber optic Michelson sensor was embedded in composite beams to sense the internal strain and points of failure of the composite structures. The bending deformation and matrix cracking were investigated by four-point bending tests of cross-ply composite beams with the embedded fiber optic sensor. The failure points of composite beams were detected by using both a PZT sensor and a fiber optic sensor in order to investigate the fiber optic failure signals. The failure due to matrix cracks in a composite beam was confirmed by the edge replica method. The digital processing of the fiber optic signal was carried out to determine the strains and failure points of composite beams. The failure points were observed from the processed failure signal by high-pass filtering. The initial failure strain of the composite beam was measured and processed from the fiber optic strain signal after low-pass filtering.     

Risk of major depression in patients with chronic renal failure on different treatment modalities: A matched‐cohort and population‐based study in Taiwan

The influence of different treatment modalities on the risk of developing major depression in patients with chronic renal failure (CRF) is not well understood. We aimed to explore the incidence of major depression among patients with CRF who were on different dialysis modalities, who had received renal transplantation (RT), and those who had not yet received any of the aforementioned renal replacement therapies. We conducted a population‐based retrospective cohort study using a national health insurance research database. This study investigated 89,336 study controls, 17,889 patients with chronic kidney disease on conservative treatment, 3823 patients on hemodialysis (HD), 351 patients on peritoneal dialysis (PD), and 322 patients who had RT. We followed all individuals until the occurrence of major depression or the date of loss to follow‐up. The PD group had the highest risk (hazard ratio [HR] 2.43; 95% confidence interval [CI] 1.26–4.69), whereas the RT group had the lowest risk (HR 0.18; 95% CI 0.03–1.29) of developing major depression compared with the control group. Patients initiated on PD had a higher risk of developing major depression than patients initiated on HD (pairwise comparison: HR 2.20; 95% CI 1.09–4.46). Different treatment modalities are associated with different risks of developing major depression in patients with CRF. Among renal replacement therapies, patients who have had RT have the lowest risk of developing major depression. Patients who initiate renal therapy on PD may have a higher risk of major depression compared with patients who initiate renal therapy on HD.